ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

DFT-guided experimental investigation of green synthesized La₁₋ₓSrₓFe₀.₇Ni₀.₃O₃ perovskites via Spirulina extract for enhanced photocatalytic activity

Manel Melouli, Omar Ben Mya, Mohammed Lakhder Belfar, Abdelkader Benmenine, Mohammed Saleh, and Nadir Dizge

Department of Chemistry, Faculty of Mathematics and Material Sciences, University KasdiMerbah Ouargla, Ouargla, Algeria

E-mail: muh.saleh89@gmail.com

Received: 22 April 2026  Accepted: 4 June 2026

Abstract:

This study introduces a novel green synthesis of Sr-doped LaFe_₀.₇Ni_₀.₃O_₃ perovskite photocatalysts using decocted aqueous extract of Spirulina platensis from Tamanrasset, Algeria. The extract, rich in phenolics and flavonoids, acts as a natural reducing and stabilizing agent, enabling eco-friendly perovskite formation without toxic reagents. La_₁₋ₓSr_ₓFe_₀.₇Ni_₀.₃O_₃ compositions (x = 0.0, 0.1, 0.2) were synthesized and characterized. The optical band gap decreased from 2.78 eV for the undoped sample to 2.50 eV for the Sr-doped compositions, surface area of 19.87 m²/g, and high crystallinity. It achieved 98.6% degradation of methylene blue under visible light in 90 min, outperforming the undoped sample (82.3% in 120 min). Density Functional Theory (DFT) calculations confirmed that Sr doping enhances electronic properties, oxygen vacancies, and adsorption energy. To the best of our knowledge, limited studies have investigated the combination of Spirulina-mediated green synthesis and DFT modeling for Sr-doped LaFe_₀.₇Ni_₀.₃O_₃ perovskites, offering a sustainable and efficient approach for solar-driven water purification.

Keywords: Green synthesis; Spirulina platensis; Sr-doped LaFe₀.₇Ni₀.₃O₃ perovskite; Visible light photocatalysis; DFT calculations

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-026-05166-w

Chemical Papers 80 (11) 13099–13112 (2026)